1. Field of the Invention
The invention relates to a method for providing service access to a user and a system for providing service access to a user.
2. Description of the Related Art
Identity management systems in general refer to an information system which can be used to support the management of identities, including establishing, describing and destroying identities or following identity activity. Identity management may be in particular used to identify an authorized access to a computer network for a user or a certain group of users. To obtain access requiring an authentication of the user to a service computer or network, an identity management protocol may be used like SAML or OpenID. A user might use a client on his local computer for requesting an identity management service. When a user requests a service requiring authentication a service provider connected to the computer of a user contacts a corresponding identity provider via its internet service provider through a redirect on the browser of the client for authentication. It is also possible that further identity providers may be also contacted by the browser of the user continuing to act as a virtual proxy between the service provider(s) and the identity providers.
However, when contacting the identity provider by a service provider through a redirect this might lead to security problems. For example attacks in form of a “denial of service” attack or even worst phishing attacks are possible. The user is taken advantage of by an attacker redirecting the user to a website which is under control of the attacker and the attacker uses the redirect function to keep himself in the middle of all communication between the user, the identity providers and/or the service providers.
To overcome this disadvantage the use of secure transport protocols or secure service protocols might be used. This provides a slightly increased security level although attacks are still possible due to a disconnect between the content to be transmitted and the security context or simply due to usability.
If, for example, identity management services are provided by the user itself or a company or enterprise the server providing these services and located within a local area network, e.g. a company network, usually needs to be accessible to and from the outside, in particular to the internet, so that users may indirectly request identity management services from outside. This opens further possibilities for attacks: attacks on transmission protocols between the user's computer and protocols and services running on a local interface of the server acting as identity service provider of the user or the company or enterprise.
In summary phishing or denial of service attacks are still possible: An identity management service is requested and the user may be intercepted by an attacker and redirected to the attacker's website during the redirect to the identity service provider. The attacker mimics the identity service provider and acts as a selective forwarder to the identity service provider. The attacker may then snoop on messages, modify commands or simply collect authentication data and/or authentication assertions for later fraudulent use with other services.
Another main problem are attacks on internal servers: when offering identity management services which are and should be publically available, users and/or computers in local enterprise or company networks may be attacked from any computer in the internet. The attacker uses the fact that the identity management services need to be available for use from any outside and inside location and therefore the corresponding servers providing these services have to be available publically. An attacker might then identify particular types of software and/or hardware in the home network of a user or in a local company network and try to use known security leaks or special characteristics of the hard- and/or software to obtain access to the corresponding network.
Since identity management services in home networks, in particular for home servers comprising home gateways or the like, are usually developed under less rigorous security requirements than their enterprise or carrier grade counterparts, software bugs or oversights may be exploited to gain access to the user data or to its local network without consent of the user.